GEOMETRYHELP

Describe 1 and 2 as they relate to the situation shown.

One side of the angle of depression is a horizontal line. 1 is the angle of depression from the airplane to the building.

One side of the angle of elevation is a horizontal line. 2 is the angle of elevation from the building to the airplane.

Quick Check

Angles of Elevation and DepressionLESSON 8-5

Additional Examples

GEOMETRYHELP

A surveyor stands 200 ft from a building to measure its height with a 5-ft tall theodolite. The angle of elevation to the top of the building is 35°. How tall is the building?

Draw a diagram to represent the situation.

x = 200 • tan 35° Solve for x.

Use the tangent ratio.tan 35° = x 200

To find the height of the building, add the height of the theodolite, which is 5 ft tall.

The building is about 140 ft + 5 ft, or 145 ft tall.

Angles of Elevation and DepressionLESSON 8-5

Additional Examples

Quick Check

Use a calculator.200 35

So x 140.

GEOMETRYHELP

An airplane flying 3500 ft above ground begins a 2° descent to

land at an airport. How many miles from the airport is the airplane

when it starts its descent?

Draw a diagram to represent the situation.

The airplane is about 19 mi from the airport when it starts its descent.

Angles of Elevation and DepressionLESSON 8-5

Additional Examples

Quick Check

3500 2 Use a calculator.

5280 Divide by 5280 to convert feet to miles.

Use the sine ratio.sin 2° =3500

x

x = 3500 sin 2°

Solve for x.